The present invention relates to an ATM (Asynchronous Transfer Mode) apparatus coping with ATM cells; particularly relating to an apparatus which collects statistical information on user traffic.
Conventional ATM processing apparatus represented by a switching system have a function of collecting user traffic, and statistical information in the ATM layer's cell level. The function is performed by a line interface unit or an ATM switching unit or other related connections, which counts the number of passed-by cells and discarded cells, etc.
However, the following problems appear for the networks in which data communication networks, such as the Internet represented by the Internet Protocol Over ATM (IPOA) or Next Hop Resolution Protocol (NHRP), are constructed on the ATM networks. Specifically, no more than cell-level traffic information can be collected due to the fact that the ATM network has no capability to identify packets, even though actual traffic is made on the packet unit basis. Thus, no statistic information on packet-level traffic can be exactly collected.
Additionally, in the ATM network, the means for collecting packet-level statistical information requires an addition of a communication apparatus, such as the ATM router to the ATM network in order to terminate the ATM Adaptation Layer (AAL) and to rebuild a packet. This results in a large increase in cost and a deterioration of the data transmission throughput for a packet-level routing process in the ATM network.